Question: Complete the square to solve for $x$. $x^{2}-9 = 0$
Explanation: Begin by moving the constant term to the right side of the equation. $x^2 = 9$ Take the square root of both sides. $x = \pm3$ So the solutions are: $x = 3 \text{ or } x = -3$ We already found the completed square: $( x + 0 )^2 = 9$